EPROM (Erasable Programmable ROM) and EEPROM (Electrically Erasable Programmable ROM)
Does what it says on the tin. Mostly used for storing firmware and OS.
EPROM is erased by exposing the chip to UV light, while EEPROM is erased by using a stronger current than that used in computer circuits.
Flash
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data. The high density NAND type must also be programmed and read in (smaller) blocks, or pages, while the NOR type allows a single machine word (byte) to be written and/or read independently.
NOR and NAND
NOR is accessed like RAM (i.e. every bit is addressed) while NAND is accessed much like a Hard Disk drive (Blocks of addressed bits)
"NOR and NAND flash get their names from the structure of the interconnections between memory cells. In NOR flash, cells are connected in parallel to the bit lines, allowing cells to be read and programmed individually. The parallel connection of cells resembles the parallel connection of transistors in a CMOS NOR gate. In NAND flash, cells are connected in series, resembling a NAND gate. The series connections consume less space than parallel ones, reducing the cost of NAND flash.
[Source: http://en.wikipedia.org/wiki/Flash_memory#NOR_memories]
When NOR flash was developed, it was envisioned as a more economical and conveniently rewritable ROM than contemporary EPROM and EEPROM memories. Thus random-access reading circuitry was necessary
RAM
Typically SRAM or DRAM.
Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit.
Static random-access memory (SRAM) is a type of semiconductor memory where the word static indicates that, unlike dynamic RAM (DRAM), it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit. SRAM exhibits data remanence, i.e data will remain on the SRAM for an extended time, but is still volatile in the conventional sense that data is eventually lost when the memory is not powered.
Memory use In Smart Phones
RAM in smart phones is used to open applications and the smart phone OS.
If you are low on RAM Memory, it means that total applications running in the background are maxed out and have to be closed.
Memory Architectures:
EPROM (Erasable Programmable ROM) and EEPROM (Electrically Erasable Programmable ROM)
Does what it says on the tin. Mostly used for storing firmware and OS.
EPROM is erased by exposing the chip to UV light, while EEPROM is erased by using a stronger current than that used in computer circuits.
Flash
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data. The high density NAND type must also be programmed and read in (smaller) blocks, or pages, while the NOR type allows a single machine word (byte) to be written and/or read independently.
NOR and NAND
NOR is accessed like RAM (i.e. every bit is addressed) while NAND is accessed much like a Hard Disk drive (Blocks of addressed bits)"NOR and NAND flash get their names from the structure of the interconnections between memory cells. In NOR flash, cells are connected in parallel to the bit lines, allowing cells to be read and programmed individually. The parallel connection of cells resembles the parallel connection of transistors in a CMOS NOR gate. In NAND flash, cells are connected in series, resembling a NAND gate. The series connections consume less space than parallel ones, reducing the cost of NAND flash.
[Source: http://en.wikipedia.org/wiki/Flash_memory#NOR_memories]
When NOR flash was developed, it was envisioned as a more economical and conveniently rewritable ROM than contemporary EPROM and EEPROM memories. Thus random-access reading circuitry was necessary
RAM
Typically SRAM or DRAM.Dynamic random-access memory (DRAM) is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit.
Static random-access memory (SRAM) is a type of semiconductor memory where the word static indicates that, unlike dynamic RAM (DRAM), it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit. SRAM exhibits data remanence, i.e data will remain on the SRAM for an extended time, but is still volatile in the conventional sense that data is eventually lost when the memory is not powered.
Memory use In Smart Phones
RAM in smart phones is used to open applications and the smart phone OS.If you are low on RAM Memory, it means that total applications running in the background are maxed out and have to be closed.
Source:[http://www.allaboutsymbian.com/features/item/Keeping_It_Clean.php]
Operating Systems
Processor